This invention relates to radiography, and more particularly, to dental or intraoral radiography. In dental radiography, one of the principal techniques utilized for producing radiographs of teeth is referred to as the paralleling or right angle technique. The paralleling technique encompasses radiographs which are taken in the periapical position (both maxillary and mandibular) as well as radiographs which are taken in the bite-wing position. Another useful technique for taking radiographs is the occlusal technique which practices the rule of isometry.
Heretofore, radiographs which have been taken in the periapical position have necessitated the use of different radiographic instrumentation than that utilized for radiographs taken in the bite-wing position. For example, radiographic instrumentation including a particular film-holding bite block for taking radiographs in the periapical position (both maxillary and mandibular) are disclosed in my patent application Ser. No. 581,237 filed Sept. 22, 1966 (now abandoned) and my U.S. Pat. No. 3,745,344. Instrumentation including a different film-holding bite block for radiographs taken in the bite-wing position is disclosed in my application Ser. No. 581,048 filed Sept. 21, 1966 (now abandoned). Instrumentation utilized in practicing the rule of isometry or the bisecting angle technique are shown in my U.S. Pat. No. 3,473,026 as well as U.S. Pat. No. 1,923,669 -- Harrison.
It will therefore be understood that different instrumentation is required depending upon whether the radiographs are being taken in the periapical, the bite-wing, or bisecting angle position. In this connection, it may be noted that the bite blocks used in the periapical position as well as the bite-wing position comprise a groove which only allows the radiographic film to be placed in a single position in the bite block. U.S. Pat. No. 2,240,336--Kreider does disclose a bite block which is utilized to hold films in the bite-wing position but also includes a slot which does allow the radiographic film to be positioned in a perapical position. However, the film is prone to move in the slot and is particularly difficult to maintain in the periapical position where only an edge of the film is received in the slot.
Of course, even if the radiographic film could be positioned in both the periapical and bite-wing position within a single bite block, it would still be necessary to move the x-ray beam with respect to that bite block so as to assure proper coverage of the radiographic film by the beam. In this connection, various alignment assisting mechanisms have been utilized including linear rods and alignment frames which may be circular when a circular beam is utilized as disclosed in the aforesaid abandoned applications and by U.S. Pat. No. 3,743,026 as well as a rectangular frame as disclosed in my U.S. Pat. No. 3,745,344. However, these alignment mechanisms would be ineffective to properly direct the x-ray beam for both periapical and bite-wing positions of the radiographic film. Moreover, these alignment mechanisms require a fair degree of training and experience to properly utilize. However, with the increased demands on the time of dentists, it is often desirable to leave the radiography to dental hygienists or assistants, some of which may be lacking in experience.